#include <stdio.h>
#include <string.h>
int main()
{
    char s[100];
    gets(s);
    int count = 0;
    for (int i = 0; i < strlen(s); i++)
        if (s[i] >= '0' && s[i] <= '9' || s[i] >= 'A' && s[i] <= 'Z' || s[i] >= 'a' && s[i] <= 'z') count++;
    printf("%d", count);
    return 0;
}
